Needle guard clip with heel

ABSTRACT

A needle guard clip assembly has a clip and a spring, the clip having a first wall with a needle passage therethrough, a generally parallel second wall, a strut connecting the two walls, and a heel extending from the first wall. The walls, strut, and heel are an integral piece. The spring is associated with and extends from the first wall.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.11/161,549, filed Aug. 8, 2005, which issued on Aug. 28, 2012 as U.S.Pat. No. 8,251,950, the disclosure of which is incorporated herein byreference in its entirety.

1. Field of the Invention

The present invention relates to medical needles (such as hypodermicneedles, catheter insertion needles or cannulae, or other sharp-tippedhollow or solid cannulae) and, more particularly, to needle guards toprotect users and others from the sharp tip of the needle afterwithdrawal from a patient.

2. Description of Prior Art

A variety of different needle guards have been developed or proposed toprotect, i.e., to enclose or otherwise shield, sharp needle tips inrecognition of the need to reduce or eliminate accidental needle-sticks.Some needle guards include a housing to enclose essentially the entireneedle shaft and needle tip, such as the PROTECTIV Safety I.V. Catheterbeing marketed by Medex, Inc., the assignee of the parent applicationhereof (which subsequently merged with and into Smiths Medical ASD,Inc.). Others include a clip that moves along the needle shaft toenclose the tip after use, such as shown in U.S. Pat. No. 6,652,486.Still other needle guards provide a housing that moves along the needleshaft with an enclosed active element to secure a distal portion of theneedle with the tip inside the housing. Particularly advantageous formsof these needle guards include as the active element a canted-plate asdescribed in U.S. Pat. No. 5,322,517.

In the canted-plate device of the '517 patent, a housing is providedthrough which the needle passes. Within the housing, a canting plate isdefined by a wall with an aperture to slidably receive the needle shafttherethrough in a first state but which grips or bites into the needleshaft in a second, tilted or canted state relative to the firstposition. A second wall is connected to the first wall via anintermediate wall to define a generally rigid, single piece clip. Thesecond wall includes a portion to ride along the needle shaft to holdthe clip in the first state. When the needle tip is pulled into thehousing and past the second wall portion, the clip can tilt into thesecond state such that the canting plate grips the needle shaft toprevent the needle from being pulled any further. Also, the second wallblocks the needle tip to prevent the needle from being pushed back outof the housing. A biasing spring is provided, bearing against the firstwall, to urge the clip to the second state. The clip second andintermediate walls are to one side of the needle shaft in the firststate with the spring to the other side of the needle shaft. While theclip design of the '517 patent has many advantages, further improvementsand enhancements are desired.

One attempt to build upon the clip design of the '517 patent is shown inU.S. Pat. No. 6,280,419 which includes features intended to allow use ofthe clip with a guide wire. What is understood to be a commercialembodiment of the device of the '419 patent is the Arrow Radial ArteryCatheterization device. The commercial embodiment is believed to havedrawbacks including that its design also imposes significant drag forceon the needle shaft, which make it difficult and undesirable to use.

Further, some needle guards are intended to be used with catheterassemblies. With such needle guards, it is advantageous to have aportion of the needle guard hold to the catheter hub while the needleprojects out of the catheter tube, but to thereafter allow for readyremoval of the needle guard upon withdrawal of the needle to thetip-protected position. One proposal is to provide a nose section of theneedle guard with a pair of cooperating members extending from theneedle guard housing. The cooperating members are sized to fit withinthe catheter hub and to normally define a passageway between themembers, which is sized to slidably receive a needle shaft therethrough.One or both of the members has a detent at its distal end receivable ina respective radially outwardly extending recess formed in the interiorwall of the catheter hub. The detent gives the member(s) the appearanceof a duckbill. As will be appreciated, at least the distal portion ofthe catheter hub interior surface is tapered to female luer standards.The recess will be distal of the luer tapered surface and, when in thecatheter hub, the detent(s) normally fit within the recess. When theneedle shaft is removed from the passageway, one or both of the duckbillmembers is able to easily flex such that a slight tug on the housingcauses the duckbill to yield against the recess allowing the needleguard to begin to come away from the catheter hub. But when the needleshaft is present, flexing of the members is limited such that theholding force is very high. The detents define an outer diameter of theduckbills sized to fit within the radially outwardly extending recesses.The inner diameter of the luer tapered surface, however, is smaller overa significant portion of its distal extent than the duckbill outerdiameter. As a consequence, the duckbill members will remain flexed andwill drag or scrape against the catheter hub interior surface duringcontinued removal, which results in a feel and higher removal forcesthan might be desired by the medical practitioner.

The Arrow Radial Artery Catheterization device is an example of aduckbill design. But, the needle guard housing thereof cannot rotaterelative to the catheter hub. Each duckbill detent has its own, limitedcircumferential length recess in the catheter hub, which thus holds theduckbill against rotation. It is often desirable to be able to rotatethe needle guard housing relative to the catheter hub. As an example, itmay be useful to rotate the components to thread the catheter tube intothe patient. One proposed solution is to provide a continuous radiallyoutwardly extending annular groove in the catheter hub such that theduckbill detent(s) may rotate therein as discussed in U.S. Pat. No.6,221,047. But, in addition to the scraping problems mentioned above, acomplete circumferential annular groove or recess in the catheter hub isbelieved to present manufacturing and product performance issues. Evenone of the named inventors of the aforementioned '047 patent seeminglyrecognized the latter problem, and so subsequently proposed to go withthe limited length recess such that the detent(s) would be inhibitedfrom rotation within the catheter hub as discussed in U.S. Pat. No.6,689,102. There is thus still a need for a viable rotatable solutionfor the duckbill, as well as a need to reduce or eliminate the problemproduced by the scraping of the detents with the inner surface of thecatheter hub during removal.

SUMMARY OF THE INVENTION

In accordance with one of the principles of the present invention, thereare provided canting-plate needle guards that have desired improvementsand enhancements as compared to prior canted-plate designs. To that end,in one aspect, the needle guard includes a spring member, which may be aleaf spring, extending from the first wall past an edge of theintermediate wall, which may be defined by one or two struts, and intooperative engagement with a bearing surface, with the extending portionof the spring member and the intermediate wall advantageously being tothe same side of the needle. The bearing surface may be defined in or bya housing which contains the clip and spring member. The spring memberand its operative relationship with the clip and/or the housing isbelieved to provide the appropriate biasing of the clip in a low profileand without imposing undue drag forces between the clip second wallportion and the needle shaft.

In a second aspect, the strut(s), i.e., the intermediate wall,advantageously extends from the first wall at an angle of less than 90degrees relative to the first wall, and more advantageously, at an angleof between about 83 and about 87 degrees. That angling allows for anincrease in the degree of clip rotation before gripping to the needleshaft to more reliably block or cap the needle tip. In a third aspect, astylus is provided at the second wall to bear against the needle shaftthereby providing a smooth surface and reducing drag on the needle whilealso improving the tactile and audible feel and behavior of the needleguard. In a fourth aspect, the second wall may be generally L-shaped todefine a lip at a free end which projects toward the first wall. The lipis disposed on one side of the needle shaft in the first state of theclip and assists in confining or capping the needle tip in the secondstate of the clip. The stylus may be a coined portion of the L-shapedwall.

In a fifth aspect, a heel extends from the first wall, with the heel andfirst wall disposed to opposite sides of the intermediate wall or strut.A ledge is provided with the heel abutting the ledge in the first stateof the clip and pivoting about the ledge as the clip moves from thefirst state to the second state to thereby enhance its performance.

It will be appreciated that were the needle shaft to deflect in responseto the force of the grip of the first wall, the shaft would seek toalign with the aperture of the first wall, thus reducing the grip. Tothis end, in a sixth aspect, a needle support is fixedly positionedadjacent a plane transverse to a cylinder defined by the needle shaft soas to limit deflection of the needle shaft when the needle tip has beenpulled into the needle guard. Thus, in the second state of the clip, thetendency of the needle shaft to flex is minimized by the needle support.

In addition to the foregoing aspects of the present invention, which canbe used independently or in any desired combination, the presentinvention provides improvements to needle guards which can be used notonly with canting-plate clips but with other needle guard designs aswell. By way of example, needles or catheter assemblies with needles areusually provided with a protective sheath to enclose at least the needletip and to overlie at least a portion of the needle guard prior to use.Gripping the needle hub to which the needle is affixed and the sheathportion overlying the needle guard to pull the sheath off could lead toinadvertent activation or removal of the needle guard from the catheterhub, thereby rendering the device unfit for use. One proposed solutionis to provide a shroud on the needle hub that substantially encloses theneedle guard when the needle hub is adjacent thereto. Thus, if thesheath portion overlying the needle guard is gripped, the force thereofwill be transmitted to the shroud, rather than the needle guard, toreduce the likelihood of inadvertently activating the needle guard orpulling the needle guard loose from the catheter hub. That shroud,however, interferes with ready removal of the needle from the catheterin use. To that end, in accordance with another principle of the presentinvention, a split shroud is provided which overlies opposed portions ofthe needle guard but leaves another portion, such as finger tab thereof,exposed through the split shroud so as to allow for ready removal of theneedle from the catheter in use.

In accordance with a yet further principle of the present invention, itis desired to hold the needle hub and needle guard from rotation beforethe needle guard is deployed so as to add stability when beginning aneedle stick. To this end, cooperating structure, such as a lug with anon-circular periphery and a non-circular periphery recess, are providedon the respective confronting faces of the needle hub and needle guard.The cooperating structure engages when the needle hub is adjacent theneedle guard, to thus hold them against relative rotation. As thecomponents move apart, however, the cooperating structure no longerengages, thus allowing for such rotation.

In accordance with a still further principle of the present invention,and in particular for use with a catheter assembly, an improved needleguard duckbill catheter hub release mechanism is provided in which thereis relative rotation between the needle guard and the catheter hub andwithout disadvantageous scraping during removal. To that end, an annularradially inwardly extending rib is provided in the catheter hub forselective engagement by the detent(s) of the extending cooperatingmembers, rather than a radially outwardly extending recess or groove.The rib is distal of the luer tapered portion of the catheter hubinterior surface, and the duckbill detents may be sized so as not tounduly scrape against the catheter hub interior on removal, yet to holdbehind the rib prior to removal. The rib, which may be continuous orhave gaps therein, presents advantages in manufacture and in performanceof the device over the recesses or grooves characteristic of priorduckbill release mechanisms.

By virtue of the foregoing, individually and in various combinations,there are thus provided canting-plate needle guards that haveimprovements and enhancements as compared to prior canted-plate design.Also, by virtue of the foregoing, individually and in variouscombinations, there are thus also provided improvements to needle guardswhich can be used not only with canting-plate clips, but with otherneedle guard designs as well. These and other objects and advantages ofthe present invention shall be made apparent from the accompanyingdrawings and the description thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the general description of the invention given above, andthe detailed description of the embodiments given below, serve toexplain the principles of the present invention.

FIG. 1 is a perspective view of one embodiment of a needle guard definedby a canting plate clip with a leaf spring member in accordance with theprinciples of the present invention;

FIGS. 2A and 2B are cross-sectional views of a second embodiment of aneedle guard having a housing and the clip of FIG. 1, showing the clipin first and second states with a sharp tip of a needle exposed andprotected, respectively, for purposes of explaining certain principlesof the present invention;

FIGS. 2A′ and 2B′ are detail views of portions of FIGS. 2A and 2B,respectively for purposes of explaining certain principles of thepresent invention;

FIGS. 3A-3C are side views of a catheter assembly incorporating thevarious aspects of the present invention including a third embodiment ofa needle guard for a needle of the catheter assembly;

FIG. 4A is a perspective view of a nose portion of the needle guardhousing of FIGS. 3A-3C for purposes of explaining certain additionalprinciples and aspects of the present invention;

FIG. 4B is a rear view of the proximal aspect of the nose portion ofFIG. 4A;

FIG. 5 is a cross-sectional view of the catheter hub of FIGS. 3A-3C forpurposes of explaining the duckbill catheter hub release mechanismfeature of the present invention;

FIGS. 6A-6D are cross-sectional views of the catheter assembly of FIGS.3A-3C for purposes of illustrating operation of the duckbill catheterhub release mechanism of the second embodiment of the needle guard inaccordance with certain principles of the present invention;

FIGS. 7A and 7B are end views of the confronting faces of the needleguard and the needle hub, respectively, of FIGS. 3A-3C, for purposes ofillustrating an anti-rotation feature of the present invention;

FIG. 7C is a cross-sectional, partial view as taken along lines 7C-7C ofFIG. 7B, showing the needle hub and needle guard housing of FIGS. 7A and7B in engagement with one another for purposes of explaining theanti-rotation feature of the present invention;

FIG. 8 is a perspective view of the needle hub and needle cannula ofFIGS. 3A-3C illustrating a shroud at the distal end of the needle hub;and

FIG. 9 is a cross-sectional, partial view of the catheter assembly ofFIG. 3A with a protective sheath for purposes of explaining operation ofthe shroud in accordance with certain principles of the presentinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

With reference to FIG. 1, there is shown one embodiment of a needleguard 10 including a canted-plate clip 12 and a spring member 14. Clip12 includes a first wall 16 with an aperture 18, such as a circularhole, therethrough and a second wall 20 interconnected by anintermediate wall 22 shown herein as comprising first and second struts24, 26, each having a respective inboard edge 27, 28 extending betweenwalls 16 and 20 to define an aperture 32 therebetween, and outboardedges 29, 30. Extending from first wall 16 is a heel 34 (shown in dashedline in FIG. 1) such that first wall 16 and heel 34 are disposed toopposite sides of the struts 24, 26. Second wall 20 may have a lipportion 36 projecting generally toward first wall such that second wall20 has a generally L-shape to it. The outer corner surface 37 of theL-shape second wall 20 may be coined so as to define thereat an arcuatestylus 38. Clip 12 is advantageously an integral component of rigidmetal (an example of which is stainless steel) or plastic.

Although clip 12 is depicted in FIG. 1 as including two discreet struts24, 26, those skilled in the art will recognize that alternativeembodiments of the clip 12 may include only strut 24, or only strut 26,as the intermediate wall 22. Further, the strut 24 or 26 could be widerthan depicted in the Figures, and could be so wide that they merge into,or it forms, a solid wall extending between the first and second walls16, 20. In that case, an alternative spring member (not shown) extendingpast outer edge(s) 29 or 30 could be used.

Although spring member 14 could take any desired form of stored energydevice, such as a coil or other wound spring, compressible foamsubstance or other material, or a compressible bladder, by ways ofexample, it will be described herein in the advantageous form of a leafspring having a first end 40 with an opening 41 associated with an innersurface 42 of clip first wall 16 so as to overlie aperture 18 thereof,and having an elongated leaf 44 extending from the first wall 16 pastthe edges 27, 28 of struts 24, 26 through aperture 32 to a free end 46of the leaf 44. Spring member 14 could be an integral part of clip 12,such that first end 40 is part of first wall 16 with leaf 44 extendingtherefrom. In that case, leaf 44 is advantageously thinner and moreresilient than first wall 16 for purposes hereinafter to be described.Or, as shown in FIG. 1, spring member 14 is a separate, resilientcomponent with first end 40 bearing against, and advantageously securedto, such as by welding or the like, inner surface 42.

With reference to FIGS. 2A and 2B, there is shown a second embodiment ofa needle guard 50 for a needle 52, such as a hollow hypodermic needle, ahollow or solid catheter insertion needle, or other similar sharpcannulae, attached to and extending from a needle hub 54, which in thisembodiment is shown as adapted for a hypodermic needle thus defining afemale luer lock attachment but could also or alternatively define aflash chamber. Needle 52 has a needle shaft 56 secured to and extendingfrom needle hub 54 to a distal, sharp tip 58. While not required, theshaft 56 may be of a constant cross-sectional diameter. Needle guard 50includes a housing 60 having a proximal opening 62 and a distal opening64 sized to slidably receive the shaft 56 of needle cannula 52 throughthe housing such that in a first position of needle 52, sharp tip 58 maybe distally exposed as shown in FIG. 2A, or in a second position ofneedle cannula 52, sharp tip 58 is pulled back (by either pulling needleshaft 56 proximally or pushing housing 60 distally, both referred toherein as proximal movement of needle cannula 52) into housing 60 asseen in FIG. 2B. Clip 12, wherein aperture 18 thereof is nominally sizedrelative to needle shaft 56 to selectively slidably receive or gripsame, and spring member 14 of needle guard 10 of FIG. 1 are included asthe active element to protect tip 58 within housing 60 as will now bedescribed.

Clip 12 is situated within housing 60 such that aperture 18 is generallyaligned along the longitudinal axis 65 of needle cannula 52, which axisis also defined between openings 62 and 64 of housing 60 and such thatspring member 14 extends into operative engagement with a bearingsurface 68 defined, for example, along an inner wall 70 of housing 60.Leaf 44 of spring member 14 and intermediate wall 22 are thus to thesame side of needle shaft 56. Clip 12 has a first state, shown in FIG.2A, in which first wall 16 is positioned generally vertically, althoughadvantageously over-center distally, to allow needle shaft 56 to beslidably received through aperture 18 such that the inner periphery 18′of aperture 18 does not bite or grip into needle shaft 56 as seen inFIG. 2A′. In that first state of clip 12, second wall 20 has a portion,advantageously stylus 38 thereof, adapted to bear against shaft 56, andheel 34 is adjacent inner surface 70 and abutting ledge 72 of housing60. When needle 52 is in the first position with tip 58 extendingdistally beyond clip 12, and particularly beyond opening 64 of housing60, shaft 56 is in bearing relationship with stylus 38.

Spring member 14 biases clip 12 to cant first wall 16 proximally towarda second state shown in FIG. 2B with the needle 52 in the secondposition with sharp tip 58 of needle 56 within housing 60 such that tip58 thereof is proximal of lip 36. Once tip 58 passes lip 36, heel 34pivots about ledge 72 as first wall 16 cants to bring aperture periphery18′ into biting engagement with shaft 56 to thereby grip same, as seenin FIG. 2B′, to resist further proximal movement of needle 52 relativeto housing 60. Second wall 20, and especially lip 36 thereof, movesthrough and beyond axis 65 to go beyond tip 58 as seen in FIG. 2B, suchthat second wall 20 now confronts and thus blocks tip 58 from reemergingdistally from housing 60. Lip 36 cooperates to confine tip 58 should itbe able to move distally by some amount such that tip 58 is capped byclip 12 in the second state thereof.

As seen particularly in FIG. 2A, intermediate wall 22 is not at a rightangle to first wall 16. Rather, intermediate wall 22 extends at anincluded angle a of less than 90 degrees, and advantageously betweenabout 83 degrees and about 87 degrees, therefrom and towards needleshaft 56. The angling of the intermediate wall 22 allows first wall 16to be slightly distally over-center or tilted (depending upon the gaugeof needle 52) so that the degree of clip rotation to achieve the secondstate is increased as compared to a vertical wall 16 as in priordevices. The distal tilting is only a few degrees with hole 18 sized notto bite into needle shaft 56 when wall 16 is distally tilted. Theincreased degree of clip rotation helps assure that sharp tip 58 will becapped, even in the worst-case orientation of tip 58 as shown in FIG.2B. Advantageously, needle 52 will be oriented 90° or 180° from thatshown in FIG. 2B. Also, by making the included angle between walls 16and 22 less than 90°, wall 22 typically angles towards needle shaft 56such that the clip 12 is not as likely to bind against housing 60 evenwith larger gauge needles 52. Also, heel 34 may be at an angle of about90 degrees to wall 22 such that heel 34 and wall 16 need not becoplanar.

In the second position of needle 52, with clip 12 in the second state,it will be appreciated that there is a flexing force on the distal tipend 58 of needle 52 which attempts to align that portion of needle shaft56 with aperture 18. Were the shaft 56 to flex in that manner, therecould be a reduction or loss of bite of periphery 18′ on shaft 56, suchthat needle 52 might be able to be pulled proximally out of needle guard50. To reduce that possibility, a needle support 80 is provided adjacenta plane 82 extending transverse, and possibly tangent, to the cylinder84 defined by needle shaft 56 in the first position thereof (see FIG.4B). Needle support 80 may be defined at the end of an integralprojecting member 88 of housing 60, and advantageously may include aseat 90 (FIG. 4A) sized to slidably receive a portion of needle shaft 56thereon. Seat 90 may be a slot or groove that complements thecylindrical shape of the outer surface of the needle shaft 56. Inaddition to the needle support 80, the needle 52 is also supported bythe proximal opening 62 in the housing 60. These two points (needlesupport 80 and proximal opening 62) cooperate to hold needle 52 leveland secure, and allow for the clip 12 to exert a gripping force onneedle shaft 56 without adverse flexing thereof. A flex-limit stop inthe form of a rib 91 (shown in dashed line in FIG. 4A as a lateral rib,but could be a longitudinal rib) may be included on the upper surface ofprojecting member 88 or, alternatively, a flex-limit stop rib 91′ (shownin dashed line in FIGS. 2A and 2B) could be included as part of thehousing interior surface 70 above member 88 to limit flexing(advantageously to 0.006″) of member 88 such as from leveraging ofneedle shaft 56.

Housing 60 has a barrel or canister proximal portion 94 and a distal capportion 96. Canister portion 94 includes inner wall 70 (and rib 91′ ifprovided) and back wall 98 with opening 62 and a mouth 100 sized tomatingly receive cap 96 thereto. Cap 96 includes opening 64, and isadvantageously secured to mouth 100 of canister 94, such as by snap-fit,press-fit, and/or adhesive or ultrasonic welding. Canister 94 and cap 96may have any desired cross-sectional shape, such as generally circular,such that housing 60 is generally cylindrical. Advantageously, thecross-sectional shape is rectangular by flattening opposed aspectsthereof (as seen in FIG. 7A) so as to have a low profile allowing for adesirably shallow insertion angle. Housing 60 may also include fingerridges (not shown) for needle guard 50 to facilitate use by a medicalpractitioner (also not shown). Further, although distal end 58 of needle52 is shown extending freely from needle guard 50, those skilled in theart will recognize that needle shaft 56 could also be received through acatheter assembly (such as assembly 200 of FIG. 3A). Further, whilefirst wall 16 is shown as being rectangular, first wall 16 could be anyother shape, such as square or disc-like, and aperture 18 could be otherthan a circular hole, provided tilting of first wall 16 into the secondstate of clip 12 results in gripping the needle shaft 56.

The foregoing construction and relationship of the components isbelieved to provide a needle guard that has very low drag forces, suchthat the tactile and audible sensations thereof are acceptable to themedical practitioner (not shown), while at the same time providingreliable protection of tip 58 thereby minimizing risk of accidentalneedle sticks therefrom.

In use, needle 52 is inserted into a patient (not shown) possibly with asyringe (not shown) attached to needle hub 54. After injectingmedication, for example, while housing 60 is held steady, needle hub 54and needle 52 are retracted to withdraw needle 52 from the patient andto withdraw needle tip 58 proximally into housing 60. Alternatively,needle 52 can be removed from the patient with housing 60 in placeadjacent hub 54, and then housing 60 can be pushed down along shaft 52to withdraw needle tip 58 proximally into housing 60. In either case,spring member 14 biases clip 12 toward the second state to protect theneedle tip 58. Continued attempted proximal movement of the needle 52results in increased binding force applied to needle shaft 56 therebyresisting such movement. Further, lip 36 of clip second wall 20 is nowpositioned to the other side of longitudinal axis 65 and beyond tip 58of the needle 52. As a result, attempts to push the needle 52 distallywill bring tip 58 underneath lip 36 and/or against second wall 20 toblock the needle tip 58.

With reference to FIGS. 3A-3C, there is shown a catheter assembly 200including a third embodiment of a needle guard 202 for protecting thetip 58 of needle 52. Needle guard 202 may be essentially the same asneedle guard 50 of FIGS. 2A and 2B, except that it also includes afinger tab 203 and pair of duckbills 204, 206 (see FIG. 3C) as will bedescribed. Further, needle 52 is a catheter insertion needle with aneedle hub 208 shown as defining a flash chamber. Flash chamber 208 mayinclude a vented port 210.

Catheter assembly 200 has a catheter hub 220 defining luer lugs 222 atits proximal end 224 and has a catheter tube 226 secured by eyelet 227(FIG. 5) to, and extending distally from the distal end 228 of, catheterhub 220. Needle shaft 56 extends through housing 230 of needle guard 202and through catheter hub 220 and catheter tube 226 with tip 58 exitingthe distal end 232 thereof in a first position of needle 52 as seen inFIG. 3A. Housing 230 of needle guard 202 includes proximal canister 94,but has a modified cap 234, similar to cap 96 of FIG. 2A, but defining anose portion 236 including the duckbills 204, 206. Needle support 208 ispulled proximally relative to needle guard 202 to begin to separateneedle support 208 and housing 230 of needle guard 202 as seen in FIG.3B. Continued proximal movement of needle 52 brings tip 58 into housing230 to be protected in the secured position thereof (as described inconnection with FIGS. 2B and 2B) and to also allow for release ofhousing 230 from catheter hub 220 as seen in FIG. 3C.

With further reference to FIG. 4A, extending distally from nose portion236 of cap 234 of housing 230 are a pair of cooperating members 250,252. Members 250, 252 extend to distal ends 254, 256 and definetherebetween a passageway 258 nominally sized (also referred to hereinas an inner diameter) to normally receive the shaft 56 of the needle 52freely therethrough without changing the size of passageway 258 and thuswithout normally imposing significant drag forces on shaft 56. At leastone, and advantageously both, of members 250, 252 may include a detent260 at distal ends 254, 256 to thus define segments of an annular ring262 and giving the cooperating members 250, 252 the shape of respectiveduckbills 204, 206. Detents 260 may be distally chamfered as at 263.

With reference to FIG. 5, it will be seen that catheter hub 220 includesan inner chamber 264 defined by interior surface 266 of catheter hub 220having a proximal portion 267 tapered in accordance with ISO or otherapplicable standards for female luers. A generally annular rib 268extends radially inwardly from interior surface 266 into chamber 264.Rib 268 is advantageously distal of luer tapered portion 267 so as notto interfere with male luer taper connections to catheter hub 220Annular rib 268 and detents 260 cooperate to hold needle guard 202 tocatheter hub 220 in the first position of needle cannula 52 (FIG. 3A)and to allow for release thereof by moving needle cannula 52 proximallytowards the second position (FIG. 3C). In this regard, and with furtherreference to FIG. 6A, it will be seen that in the first position ofneedle cannula 52, shaft 56 thereof is in passageway 258 thus limitingthe ability of either or both of cooperating members 250, 252 tocompress (i.e., to flex radially inwardly). At the same time, detents260 define an outer diameter of annular ring 262 that is slightlygreater than the inner diameter of annular rib 268 and which may closelycorrespond to the inner diameter of catheter hub interior surface 266just distal of annular rib 268 as at 270. Thus, with needle shaft 56between cooperating members 250, 252 as seen in FIG. 6A, detents 260provide a generally rigid hold to catheter hub 220 by cooperating withthe distal-facing surface 272 of rib 268. Even as needle cannulaprogresses proximally to bring tip 58 towards housing 230, as seen inFIG. 6B, shaft 56 still provides a block to the radially inwardlyflexing of members 250, 252.

With the needle cannula 52 in the first position (FIG. 6A), detents 260are seated past rib 268 in catheter hub 220 with a light frictional fitthat desirably allows the healthcare user (not shown) to rotate catheterhub 220 relative to needle guard 202. It is not until needle shaft 56 iseffectively proximally beyond passageway 258, such as with tip 58protected by needle guard 202 in the second position of needle 52 asseen in FIG. 6C, that either or both of members 250, 252 are easilyflexed. As a consequence, continued proximal pulling on needle guard 202causes one or both of duckbills 204, 206 to easily flex enough thatdetents 260 overcome annular rib 268, and to then flex or uncompressback to the nominal position. As the interior surface 267 portion istapered in accordance with luer standards, the minimum inner diameterthereof is generally not less than, and is advantageously larger than,the maximum outer diameter defined by detents 260, such that the detentsgenerally will not adversely scrape on surface 266 proximal of rib 268as the members 250, 252 are removed. Thus, needle guard 202 is allowedto easily come away from catheter hub 220, as seen in FIG. 6D, withoutany adverse feel or scraping and without any specific, difficult orstrong tugging action of the user (not shown). Similarly, with needleshaft 52 out from within passageway 258, duckbills 204, 206 may beeasily loaded into catheter hub 220 by pushing them into hub 220 (orpushing hub 220 over duckbills 204, 206) such that detents 260 impactagainst rib 268 to cause the cooperating members 250, 252 to flexslightly until detents 260 are distally beyond rib 258 at which timethey flex back out to lightly hold to catheter hub 220. Needle shaft 52may then be loaded to resist inward flexing of members 250, 252 greatlyincreasing the holding force. Alternatively, with shaft 52 in place,duckbills 204, 206 could be forced into hub 220. Chamfers 263 may helpwith loading duckbills 204, 206 into catheter hub 220.

Use of rib 268 overcomes drawbacks associated with prior recess-basedduckbill release mechanisms. To that end, the rib is easier tomanufacture and avoids requiring detents that are so large diametricallythat they might drag or scrape on the interior surface of the catheterhub during removal.

The size of the passageway 258 may be closely dimensioned to thediameter of needle shaft 56 so the passageway 258 is largely taken up bythe presence of needle shaft 56. Compression or other inward flexing ofthe cooperating members 250, 252 is thus limited, thereby restrictingrelease of cooperating members 250, 252 from catheter hub 220. Toleranceof the gap between the relative inner diameter of passageway 258 ofcooperating members 250, 252 and the outside diameter of needle shaft 56may be selected to reduce the likelihood of removal of the duckbills204, 206 from catheter hub 220 when needle 52 is present. Thesetolerances may vary for different gauge needles although clearances ofbetween 0.0065″ and 0.0135″ are advantageous.

Members 250, 252 are shown defining a split cylinder. While they couldbe half-moon in cross-section, advantageously, each member 250, 252 isarcuate in cross-section and has an internal, depending longitudinalridge 280 (FIG. 4A) to define, in effect, the inner diametrical size ofthe passageway 258. To that end, the radial depth of each ridge 280 maybe selected based upon the gauge of needle 52, with the radial depth ofridge 280 being inversely related to the gauge of the needle 52 suchthat the radial depth is larger for small gauge needles and vice versa.Ridges 280 might be eliminated altogether for larger gauge needles 52.The arcuate shape and selective depth of ridges 280 to define the innerdiameter of passageway 258 results in a generally consistent level offorce between the duckbills 204, 206 and catheter hub 220 across a rangeof needle gauges, such that the medical practitioner (not shown) willhave generally the same sense of feel and touch with the devices acrossa range of gauges. Cooperating members 250, 252 may be upper and lowersegments of a split cylinder, or may define respective large and smallaspects and/or side to side segments of a split cylinder. Moreover,while they are both described as being able to flex and with detents attheir distal ends, it will be recognized by those of skill in the artthat only one of the members may be resilient enough to easily flex,only one member may include a detent, and/or the detent(s) may be awayfrom the distal end(s). Also, while rib 268 is shown as being generallycontinuous, it may have one or more gaps (not shown). Advantageously,any such gap(s), if provided, would each be smaller than acircumferential width of the detent 260.

The needle guard duckbills 204, 206 and catheter hub rib 268 cooperateto define a duckbill release mechanism which, as are shown herein, maybe combined with an active element to protect needle tip 58 in the formof a canting-plate clip. However, the duckbill release mechanism of thepresent invention is not limited in use to such active elements, but maybe used with other clip designs and even non-clip-based needle guardssuch as those including housings that served as a needle guard. By wayof example, the needle guard can be the needle guard housing of thePROTECTIV Safety I.V. Catheter being marketed by Medex, Inc., theassignee of the parent application hereof (which subsequently mergedwith and into Smiths Medical ASD, Inc.), and/or those shown in U.S. Pat.Nos. 4,762,516 and 4,747,831, or the active element can include otherstructure to grip and/or block the needle as shown in or of U.S. Pat.Nos. 4,978,344; 5,215,528; 5,332,517; 5,328,482; and 5,558,651; EuropeanPatent No. 0,352,928 B2; and U.S. patent application Ser. Nos.10/905,047 and 10/906,171. Other features of the present invention arealso not limited to needle guards based on canting-plate clips as willnow be described.

Referring to FIGS. 7A-7C, in one aspect, the needle hub 208 and housing230 include cooperating structure 300, 302 that hold them againstrelative rotation in the first position of the needle 52 to enhancestability when beginning a needle stick. More specifically, housing 230includes at its proximal face 304 a projecting lug 300, having anon-circular peripheral edge 306. A recess or depression 302, also witha non-circular peripheral edge 308, is disposed in the distal face 310of needle hub 208. As a consequence, when needle support 208 is adjacenthousing 230 in the first position of needle 52, as seen in FIG. 7C,faces 304 and 310 are confronting with lug 300 engaging in recess 302 tohold the components against rotation. When needle 52 is moved out of thefirst position, lug 300 and recess 302 disengage thus allowing forrelative rotation of hub 208 and needle guard 202. The peripheral edges306, 308 of lug 300 and recess 302 are of complementary shape andadvantageously define non-circular peripheries, such as a square, oval,or hexagon, for example. However, it will be understood that othercomplementary shapes may be used to prevent relative rotation betweenhousing 230 and needle hub 208. Further the peripheral edge 308 ofrecess 302 may include one or more notch-outs as at 312. Needle 52 issecured to hub 208 such as by adhesive 313 in adhesive well 314concentric with needle 52.

Referring to FIGS. 8 and 9, in another aspect, needle hub 208advantageously has associated with it a split shroud 320. Split shroud320 has opposed arcuate legs 322, 324 extending from the distal end ofhub 208. Legs 322, 324 are sized and positioned to overlie, and possiblyconform to, opposed portions 326, 328 of needle guard 202 (and thusopposed arcuate portions of canister 94 of needle guard housing 230 andopposed portions of clip 12) in the first position of the needle 52 asseen in FIGS. 3A and 9, and to be spaced therefrom in the secondposition of the needle 52 as seen in FIG. 3C. Advantageously, legs 322,324 are positioned such that a portion of the needle guard 220, such asfinger tab 203, is exposed therebetween in the first position of needlecannula 52 as seen in FIG. 3A. In the first position of needle cannula52, shown in FIG. 9, split shroud 320 overlies a portion of the needleguard 202, such as canister portion 94 of housing 230 and/or clip 12leaving finger tab 203 exposed. The legs 322, 324 of split shroud 320may be sized and positioned such that they engage housing 230 with afriction fit. Prior to use, a protective sheath 370 covers at leastcatheter tube 226 and possibly catheter hub 220, needle tip 58, and partor all of split shroud 320. Advantageously, split shroud 320 is disposedbetween the proximal mouth portion 372 of sheath 370 and needle guard202. As a consequence, if an end user (not shown) grips the sheathportion 372, that force will be transmitted to split shroud 320, ratherthan directly to needle guard 202, to reduce the likelihood ofinadvertently activating needle guard 202 or pulling needle guard 202loose from catheter hub 220 before the device is ready for use. Mouthportion 372 may have a gap (not shown) to expose finger tab 203.However, in use, needle 52 may be readily removed such as by pushing onfinger tab 203 exposed through split shroud 320.

In use of catheter assembly 200, sheath 370 is removed, and needle tip58 inserted into a patient (not shown) to position catheter tube 226 asdescribed, including if desired by rotation of catheter hub 220 relativeto needle guard 202, but advantageously without relative rotationbetween needle hub 208 and needle guard 202. Once positioned as desired,needle hub 208 and needle 52 are moved proximally, such as with use offinger tab 203 (exposed through split shroud 320) as is well understood,to pull shaft 56 out of the catheter tube 226 and catheter hub 220, andtoward a second position with tip 58 protected by needle guard 202.Needle guard 202 is similarly removed from catheter hub 220 leaving hub220 ready for use. Advantageously, the drag forces on needle shaft 56due to clip 12 are as low as possible. Moreover, the drag forces areadvantageously lower than the forces required to separate the duckbills204, 206 from catheter hub 202, whether or not shaft 56 is in passageway258. Still further advantageously, the force required to separate theduckbills 204, 206 from catheter hub 220 with shaft 56 in passageway 258(referred to as “catheter separation force”) is greater than, and mostadvantageously is at least twice, the force necessary to let them comeloose when the passageway 258 is not obstructed by needle shaft 56 suchas in the second position of needle 52 (referred to as “catheter releaseforce”). The catheter release force may be determined by the “duckbillfree length,” which is the length of the cooperating members 250, 252from nose portion 236 (or any continuous portion as at 380). This lengthaffects the stiffness of the cooperating members 250, 252, which in turnaffects the catheter release force. For example, the longer the duckbillfree length of a cooperating member 250 or 252, the less the stiffnessleading to a more flexible member. Also, use of the arcuate shape tomembers 250, 252, and 260 and ridges 280 provides a generally consistentlevel of catheter release force (and/or catheter separation force)across a range of gauges of needle 52. That consistency is also enhancedby the lack of scraping between detents 260 and catheter hub surface267. As can thus be seen, catheter assembly 200 provides a passiverelease of needle guard 202 from catheter hub 220. The normal activityof retracting needle hub 208 from catheter hub 220 activates needleguard 202 without any additional action by the healthcare worker (notshown). Similarly, further retraction of the needle hub 208, afteractivation, easily releases needle guard 202 from catheter hub 220without additional manipulation by the healthcare worker.

By virtue of the foregoing, individually and in various combinations,there are thus provided canting-plate needle guards that haveimprovements and enhancements as compared to prior canted-plate design.Also, by virtue of the foregoing, individually and in variouscombinations, there are thus also provided improvements to needle guardswhich can be used not only with canting-plate clips, but with otherneedle guard designs as well.

While the present invention has been illustrated by the description ofembodiments thereof, and while the embodiments have been described inconsiderable detail, it is not intended to restrict or in any way limitthe scope of the appended claims to such detail. Additional advantagesand modifications will readily appear to those skilled in the art. Forexample, while the Figures and the description herein show clip 12 ashaving a first wall 16 that cants proximally upon retraction of theneedle 52, it will be understood by those of skill in the art that clip12 could be designed such that wall 16 cants distally. Further, secondwall 20 of clip 12 could include an opening (not shown) for a guide wirebut not with clearance for needle 52 in the second sized state of clip12. Further still, stylus 38 of second wall 20 could join directly tointermediate wall 22 of clip 12, such that the stylus defines the secondwall. Further still, spring member 14 could extend past outboard edges29, 30 of intermediate wall 22 rather than inboard edges 27, 28 ofintermediate wall 22. Also, if clip 12 and spring member 14 are sizedsmall enough, they could be fitted directly into a catheter hub with abearing surface in the catheter hub. The invention in its broaderaspects is, therefore, not limited to the specific details,representative apparatus and method, and illustrative examples shown anddescribed. Accordingly, departures may be made from such details withoutdeparting from the spirit or scope of the general inventive concept.

What is claimed is:
 1. A needle guard clip assembly comprising: a cliphaving a first wall with a needle passage therethrough, a generallyparallel second wall spaced from and confronting the first wall, a strutinterconnecting the first and second walls, and a heel extending fromthe first wall; the first wall, second wall, strut and heel being anintegral piece and the needle passage being coincident with a needlepath extending in a first direction between the first wall and thesecond wall; and a spring associated with and extending from the firstwall away from the needle path to a free end, such that the free end islocated at a greater distance from the needle path than a remainder ofthe spring, the spring having a first end associated with the first walland a leaf extending from the first end and away from the needle path tothe free end, and the first end of the spring having an openingoverlying the needle passage of the clip first wall.
 2. The needle guardclip assembly of claim 1, the opening of the spring first end beinglarger than the needle passage of the clip first wall.
 3. The needleguard clip assembly of claim 1, the spring first end being integral withthe first wall of the clip.
 4. The needle guard clip assembly of claim1, at least a portion of the leaf extending alongside the heel.
 5. Theneedle guard clip assembly of claim 1, the first end being secured tothe clip first wall.
 6. The needle guard clip assembly of claim 1, thespring being secured to the clip first wall.
 7. The needle guard clipassembly of claim 1, the integral piece being rigid.
 8. A needle guardclip assembly comprising: a clip having a first wall with a needlepassage therethrough, a generally parallel second wall spaced from andconfronting the first wall, a strut interconnecting the first and secondwalls, and a heel extending from the first wall; the first wall, secondwall, strut and heel being an integral piece and the needle passagebeing coincident with a needle path extending in a first directionbetween the first wall and the second wall; and a spring associated withand extending from the first wall away from the needle path to a freeend, such that the free end is located at a greater distance from theneedle path than a remainder of the spring, at least a portion of thespring extending alongside the heel.
 9. The needle guard clip assemblyof claim 8, the needle path having a size defined by a needle-likestructure that is configured to extend through the clip; and no portionof the spring touching the needle path so as not to bear against aneedle extending along the needle path.
 10. The needle guard clipassembly of claim 8, the spring being secured to the clip first wall.11. The needle guard clip assembly of claim 8, the integral piece beingrigid.
 12. A needle guard clip assembly configured to interact with aneedle-like structure, the clip assembly comprising: a clip having afirst wall with a needle passage therethrough, a generally parallelsecond wall spaced from and confronting the first wall, a strutinterconnecting the first and second walls, and a heel extending fromthe first wall; the first wall, second wall, strut and heel being anintegral piece and the needle passage being coincident with a needlepath extending in a first direction between the first wall and thesecond wall, the needle path having a size defined by the needle-likestructure that is configured to extend through the clip; and a springassociated with and extending from the first wall to a free end, thespring having an opening overlying the needle passage of the clip firstwall and being larger than the needle passage of the clip first wall, noportion of the spring touching the needle path so as not to bear againsta needle extending along the needle path.